1. Field of Invention
The present invention relates to wireless information delivery systems, and in particular to delivering software and operating parameter updates to receivers in a broadcast information delivery system.
2. Related Art
Consumer-oriented wireless (radio) information systems that deliver selected programs to users are becoming available. Such information delivery systems typically include a mobile electronic device (e.g., a portable radio receiver) that receives and stores information contained in a program information signal. The mobile device later outputs selected stored programs that the user designates. U.S. Pat. Nos. 5,406,626, 5,524,051, 5,751,806, 5,809,472, 5,815,671, and 5,590,195 describe features of such information delivery systems and are incorporated herein by reference.
Many mobile electronic devices are read-only memory (ROM) based. Thus the control software first stored in each device at the point of manufacture cannot be changed. Other mobile devices (e.g., cellular telephones, personal digital assistants, and portable audio players) contain random-access memory (RAM) data storage areas that can be modified. For instance, cellular telephones often contain a user-customized directory that contains the names corresponding to the user's frequently called telephone numbers.
For devices in which software and other stored operating parameters can be modified, the modification is often performed using a one-to-one connection (e.g., wired or wireless modem) to a personal computer. For example, mobile computers (e.g. laptop computers) derive much of their utility by allowing easy and automatic synchronization of stored data files with identically named data files that reside on a larger, fixed computer (e.g. a desktop computer). Similarly, portable audio players, such as the Rio™ portable player manufactured by Diamond Multimedia Systems, Inc., derive nearly all utility from their changeable data content. For example, several songs can be downloaded from a stationary terminal, such as a personal computer, to the smaller, mobile device which is then subsequently used to output the song to the user.
The operating software in some portable electronic devices, such as personal digital assistants, can be modified by downloading new software over the one-to one link that is subsequently stored and executed by such devices. This modification capability significantly extends the device's utility because new software can enable the device to offer features and services not originally available when the device was manufactured. However, the updating typically requires the use of acknowledged transfers (handshaking) of fixed-size blocks of data. Without such acknowledged transfers, correct software upgrades cannot be guaranteed. Furthermore, in information delivery systems in which many mobile units are in use, software upgrades for many devices are delayed, or do not occur, because users do not modify the software in a timely fashion. What is required is a more reliable method of updating software in mobile electronic devices.